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Python Python Collections (2016, retired 2019) Dictionaries String Formatting with Dictionaries

Posted by Mohammad Zryab
Mohammad Zryab
4,109 Points

Why are we unpacking the items in the for loop and not the actual dictionary?

Here is my code:

# Example:
# values = [{"name": "Michelangelo", "food": "PIZZA"}, {"name": "Garfield", "food": "lasagna"}]
# string_factory(values)
# ["Hi, I'm Michelangelo and I love to eat PIZZA!", "Hi, I'm Garfield and I love to eat lasagna!"]

template = "Hi, I'm {name} and I love to eat {food}!"
values = [{"name": "Michelangelo", "food": "PIZZA"}, {"name": "Garfield", "food": "lasagna"}]

def string_factory(values):
    new_list = []
    for things in values:
        new_list.append(template.format(**things))
    return new_list

My question here is, in the for loop why are using "**" for things and not for values? Because things is not a dictionary that we can unpack whereas values is.

1 Answer

Chris Freeman
MOD
Chris Freeman
Treehouse Moderator 68,423 Points
Chris Freeman
Chris Freeman
Treehouse Moderator 68,423 Points

values is a list that cannot be unpacked with "**". The double-asterisk is used to turn the things dictionary into the key/value pairs needed for the format statement. The if statement will automatic iterate over the values list.

Mohammad Zryab
Mohammad Zryab
4,109 Points

Got it - completely overlooked that values was a list.